Chart calculating machine



Aug. 30, 1938. J. B. McGAY CHART CALCULATING MACHINE 7 Sheets-Sheet 1 Filed NOV. 2, 1933 Aug. 30, 1938. J. B. McGAY CHART CALCULATING MACHINE 7 Sheets-Sheet 2 Filed Nov. 2, 1933 3mm JOHIYBJV G/IX (lama Aug. 30, 1938. J. B. M GAY CHART CALCULATING MACHINE Filed Nov. 2, 1933 7 SheetsSheet 3 INVENTOR JOH/Y amem.

Aug. 30, 1938. J. B. McGAY I CHART CALCULATING MACHINE Filed Nov. 2, 1933 7 Sheets-Sheet 4 IN VEN T OR. JO/f/Y B. [7Q Gr? 7 A TTORNEYJ uawww w Aug. 30, 1938. J. B.-M GAY CHART CALCULATING MACHINE Filed Nov.2, 1933 7 Sheets-Sheet 5 A TTORNEYJ Aug. 30, 1938. J. B. McGAY 2,128,834

CHART CALCULATING MACHINE Filed NOV. 2, 1933 7 Sheets-Sheet 6 amt BY g

Al ORNEYd" Aug. 30, 1938. J, B. McGAY CHART CALCULATING MACHINE 4 Filed Nov. 2, 1953 7 Sheets-Sheet '7 ax g m INVENTOR. JO/I /Y B. N619X MW -r WM A YTORNE Y5 Patented Aug. 30, 1938 UNITED STATES 01mm CALCULATING MACHINE John B. McGay, Tulsa Okla., usignor to Pittsburgh Equitable Meter Company, Pittsburgh, Pa., a corporation of Pennsylvania Application November 2, 1933, Serial No. 69ll,419

47 Claims.

This invention relates to an integrating apparatus particularly adapted for use in integrating the curves of orifice meter charts used for measuring the flow of fluids, although the apparatus is not limited thereto.

In measuring flows oi fluids through conduits or pipes with orifice meters, it is common practice to insert in the pipe line an orifice plate having an orifice therein to thereby provide a diiferential of pressure on opposite sides thereof and to associate with the orifice plate an orifice meter. The orifice meters in common use usually have a mechanism whereby the diiferential in pressure on opposite sides of the orifice is recorded on a chart, and the static pressure is also recorded on the same chart. The graphic records thus produced are usually recorded upon a circular chart for a twenty-four hour period, and the quantity of fluid flowing in the pipe may be computed from the difierential and static pressure curves recorded thereon.

In accordance with known laws of the flow of fluids, the average rate of flow of the fluid is equal to a constant multiplied by the square root of the product of the average absolute static pressure and the average differential pressure. across the orifice. The constant entering this computation depends on the type of fluid, the temperature thereofithe design of the particular orifice meter and many other factors as is well known in the art.

In computing the volume of fluid passed from the two pressure curves, it has been common practice to select a plurality of short time intervals on a chart to be integrated to strike an average and compute the product of the static and differential pressures for each of said intervals, to manually extract the square root of each oi these products and multiply by the meter constant, and then to sum up the results. It will be readily understood that this method of calculating volume flow is slow and laborious, is subject to human error, and is most unsatisfactory since the time intervals selected may not truly represent the average flow.

In my co-pending application for reissue Serial No. 568,484, now Patent Re. 19,009, and my application Serial No. 390,347, filed September 24, 1929, of which later application this is a continuation in part, I have disclosed a machine for accurately and rapidly integrating the static pressure and differential pressure curves of one type of oriflce meter chart, and multiplying together the integral of the square roots of the values represented by large numbers, and as the characteristics, such as the relation of pen center to chart center, and linkage between the float and pen arm, of the various types of orifice meters are diiferent, each type employs a chart that differs materially from the chart required by the other types. The

machines disclosed in the above applications are intended for integrating only one type of chart for one make of meter and cannot be used for integrating the charts of any other type of orifice meter having diiferent characteristics.

Accordingly; it is an object of the present invention to provide a machine that may be employed to accurately calculate the integral of the static pressure and differential pressure curves of various types of charts and multiply the integrals of the square roots of the values represented by the curves, which is so designed and arranged that it may rapidly and easily be adapted to integrate various types of orifice meter charts in various pressure ranges thereby producing a machine which is universal in character.

Another object of the present invention is to provide a chart integrating machine having an integrating mechanism cooperating with a plurality of interconnected tracing points having different laws of motion and a common control therefor whereby one integrating mechanism can be employed for integrating two or more types of charts.

A further object is the provision of proportional motion transmitting means between the various tracing pen centers whereby a constant ratio is maintained between the movement of the cam carriages and of the various tracing pen assemblies.

Still another object of this invention is to provide a calculating machine for orifice meter charts of diiferent types and in which a simple manual adjustment is provided to accommodate charts of the same type having widely variant static pressure ranges, or charts of different types having widely variant static pressure ranges.

Another object is to provide a chart ,calculator having a plurality of static pressure and dliferential pressure tracing points operating under different laws in conjunction with a common square root cam whereby the same integrating mechanism can be employed for integrating various types of charts.

Another object is the provision of an integrator of the type reierred to in which various cams can be used for various types of charts and in which shifting means is provided for proper cooperation of the correct cam for a given chart.

Another object is the provision of a novel motor mounting and reduction gear casing having provision for aligning the motor with the driven shaft and forming an impositive driving connection therewith.

Another object of my invention is the provision of an impositive driving connection between the chart plate and time disc whereby positive stopping of the chart plate can be accomplished without unduly straining the driving mechanism therefor.

A further object is the provision of a unitary pen assembly comprising static pressure and differential pressure curve tracing points that is readily removable yet can be quickly positioned accurately when reassembled for use, and which is not subject to accidental displacement.

Another object is the provision of an exceedingly accurate adjustment for various zero positions of the differential pressure and static pressure tracer points for compensating for temperature changes, and other changes in alignment possible, due to rough handling of the machine.

Another object of the present invention is to provide a chart integrating machine having a plurality of tracing point actuating mechanisms and novel means for coordinating the movements of these mechanisms with each other, in such manner that no lost motion exists and extreme accuracy of integration is obtained.

Another object is the provision of a tracing pen divider for retracing a curve to compensate for a constant inaccuracy therein, such as caused by loss of mercury from the orifice meter float chamber, etc.

Still a further object is to provide a novel and relatively simple means forafliidng a chart to the chart plate of an integrator and for maintaining the chart in a relatively fixed position during the integrating process.

These and various other objects of the invention will be apparent from the following description and appended claims when taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a plan view in elevation of a preferred embodiment of my invention adapted for calculation of a plurality of types of charts.

Figure 2 is a bottom view in elevation of Figure 1.

Figure 3 is a detail view partly in section on line IIIIII of Figure 2 showing the operating motor and reduction gearing for driving the time plate. a

Figure 4 is a view partly in section looking in the direction of arrow IV, Figure 3.

Figure 5 is a view partly in section on line V-V of Figure 2 showing the chart plate and driving means therefor and stop mechanism.

Figures 6, 7 and 8 are detail views of the friction clutch in the chart plate driving means.

Figure 9 is a view taken on line IX-IX Figure 1 with a portion of shaft 8| and its associated mechanism removed.

Figure 10 is a view in partial section on line x -x of Figure 1 showing details of the stop mechanism.

Figure 14 is a side elevation of the pen carriage assembly for a type F chart.

Figure 15 is a top plan view of the pen assembly shown in Figure 14.

Figure 16 is a view showing a plurality of charts superposed for purposes of comparison.

Figure 17 is a side elevation of the static pen assembly for chart of type W.

Figure 18 is a top plan view of a modification showing a non-proportional motion transmitting linkage between the type W and type F assem blies.

Figure 19.is an elevation of Figure 18.

Figure 20 is an elevation of the cam carriage mechanism and cams employed in the modification of Figure 18.

Figure 21 is a detail view of the same.

Figure 22 is a detail view of the tracing pen dividers.

Referring to the drawings, wherein like parts are designated by similar reference characters throughout the several views thereof, the mechanism of the calculating machine is carried on opposite sides of a base member I, the base member having depending sides and being adapted to be supported upon a work table or bench by suitably positioned rubber feet 2, suitably secured thereto.

The mechanism supported on the top of base member I is adapted to be enclosed in a suitable removable housing (not shown). Suitably 'carried beneath the base member I (Figure 2) is an electric motor 3 for driving the moving parts of the calculator. The motor 3 is controlled through electrical connections 3' which pass through conduits 4' suitably secured to the base I, and have suitable connections with the insulated socket 5'. The socket 5' is located in a recess 6 in the base I. In order to clarify the description of this invention, the various units thereof will be described in detail, each unit being given a heading in order that the description may be easily located.

The motor mounting and reduction gearing J assembly Referring to Figures 2, 3 and 4, the motor 3 is carried on an angle shaped frame I and is rigidly secured thereto by screws or other means, and this frame is adjustably secured to the flanged gear housing 5 which in turn is secured at its upper end to the bottom side of the base member I by bolts or other suitable means, and a hub III at the top of the housing surrounded by a fibre bushing extends through a suitable hole in base I. Suitable gaskets of rubber or similar material are interposed between the housing 5 and base member I to take up vibration. The motor shaft 6 is forced into a frictional driving member comprising a metal cup 1 having a pressed fit on worm shaft 9 and an inset 8 of rubber or similar material having a hole therein to receive the motor shaft 6. However, any other type of universal or frictional coupling may be used between the motor shaft and worm shaft.

In order to properly align the motor shaft 6 and worm shaft 9 the motor bracket 4 has a bifurcated extension 2| into which fits the externally threaded hub 22 on the bottom of cats-- ing 5. A collar 23 having holes 23' therein is threaded over this hub and bears against a suitable shoulder surrounding bifurcation 2|,

and a plurality of adjusting screws 24, prefer-' ably four in number, are threaded through the bracket extension and bear against the bottom of casing 5. Suitable washers including a rubber or similar resilient washer are interposed between collar 23 and bracket 4 to take up vibration. It will be seen that by proper adjustment of set screws 24 and of collar 23 by means of a spanner wrench (not shown) fitting into holes 23 the angular position of the motor 3 can be adjusted and the motor shaft 6 can be brought into alignment with worm shaft 9.

Worm shaft 9 is supported at either end in suitable ball bearings mounted in the gear casing 5, and is driven by the motor through the flexible coupling just described. A retaining washer 9' locked in place by set screw Ill prevents axial movement of the shaft 9. A worm |2 on shaft 9 meshes with a worm wheel |3 secured to vertical time plate shaft M which is mounted in similar ball bearings I5, l5 at the top and bottom of gear housing 5 and extends through the hub |0 which extends above the base I. A threaded coupling member H on the end of shaft I4 is adapted to receive and frictionally hold in threaded engagement a driving disc or time disc 20 against the stiff but flexible shoulder l9, and the purpose of this disc will hereinafter appear. A chart plate driving shaft or line shaft I6 is driven from vertical shaft |4 through meshing spiral gears l1, l8.

- Chart plate anddrim'ng means therefor The charts of orifice meters are usually circular and have two curves inscribed thereon, one curve representing the static pressure in the conduit below the orifice with which the meter was associated, and the other curve representing the differential pressure on opposite sides of the orifice. This invention is described in connec tion with circular orifice meter charts, and is ing bracket 3| is secured to the underside of the base by screws or other means. The chart plate shaft 32 extends through the hub 26 above the base and has a chart plate 33 suitably secured thereto at its upper end. This chart plate preferably has a covering 21 of tread stock rubber or other suitable material. The lower end of shaft 32 extends throughbracket 3| and is journalled in a suitable hub 23 on the lower side thereof. Line shaft I6 is journalled at its end in a universal ball bearing l6 secured on an extension of bracket 3| and has a worm 34 secured thereon which drives worm wheel 35 freely rotatable on shaft 32. Shaft 32 has a hollow drum 36 (Figures 5, 6, 7 and 8) pinned thereto by a suitable pin 36' and an annular expansible friction shoe 31 is located inside this drum. This shoe is split on one radius as indicated'at 33 and is bifurcated diametrically opposite, the inner bifurcation being. split at 33 and having a tapped hole 4| therein. A tapered screw 42 fits into this tapped hole 4 and as it is turned inward spreads the two portions of the shoe to develop the desired frictional resistance between shoe 31 and drum 36. Shoe 31 is rotatable relative to shaft 32 and is pinned to worm wheel 35 by a pin 43 having an enlarged head fitting into slot 44 on the shoe 31 so that when gear 35 is driven by worm 34 the shaft 32 is impositively driven through frictional coupling comprising the shoe 31 and drum 36.

The chart plate 33 is suitably secured to shaft 32, and a rounded cap or stub 45 may be threaded into the end of shaft 32 to properly center the chart which has a central hole therein. The chart to be integrated is placed on the rubber covered chart plate and is held against rotation relative thereto by prongs 46. Cooperating with prongs 46 is a retainer member 41 slidable on the stub 45 and having an annular groove 46 formed in the lower face thereof and which is adapted to receive pins 46. -When it is desired to change charts, retainer member 41 is removed, the old chart taken off, and a new chart is slipped over the projecting stub 45 on to the rubber covered plate. Retainer member 41 is then slipped over the end of stub shaft 45 and is pressed downward to cause the chart to be impaled on pins 46. Retainer member 41 and pins 46, acting in conjunction with the rubber covering cause the chart to be positively driven by plate 33.

The integrating discs and wheels As previously described the time disc or plate 2|! is. driven with shaft H by the motor 3 in synby a set screw (not shown) and upon which the I differential pressure wheel carriage and static pressure wheel carriage respectively are slidably and pivotally mounted. The static pressure wheel carriage 558 comprises alight weight tapered frame work with suitable bearings at its inner and rotatably supporting a static pressure wheel or roller 56S therein.. The static pressure carriage has an extension 6| at its other end to which is secured in spaced relation a group of cams indicated generally by numeral 628 and individually as 62a, 62b, 62c and 62d. A rod 51 extends from the opposite end of the pressure carriage and has a counter weight 53 on the end thereof for partially counterbalancing the weight of the cams. As shown, there are four cams secured to the extension 6| of the static pressure carriage, and in case the number or sizes of cams on this carriage is changed the counter weight can be adjusted along the rod 51 to properly counterbalance the weight of the cams. Movement of the static pressure carriage 55S and static pressure wheel 568 is limited to the left as seen in vFigure 12 by the bracket 5| so that the static pressureroller 55S cannot be moved closer to the center of time plate 20 than a distance corresponding to atmospheric pressure for a referbetween brackets 5| and 52 on suitable bearings .and through which the shaft 68 passes.

and at its inner end carries. a rubber covered idler wheel 84 rotatably supported in an anti-friction bearing member 65 on the carriage. The weight of the idler wheel 84 is partly counterbalanced by a weight 86 on the carriage 68 and normaly the idler wheel 84 rests with its lower surface in contact with the periphery of static pressure wheel 583. It will be seen therefore that upon rotation of the time plate 28 the pressure wheel 56S resting on and frictionally engaged by the rubber covered time plate is rotated thereby, and the idler wheel 64 which rests upon the pressure wheel 56S is rotated in turn by the pressure wheel. Preferably the time plate 28 is covered on one side with a layer of tread stock rubber, and the idler disc 64 similarly is covered with rubber on both sides.

The differential wheel carriage 61D is similarly slidably and pivotally mounted on rod 54 and carries at its inner end a'counter wheel 68D suitably supported in bearings therein. The counter wheel 88D is mounted upon a shaft 68 connected to operate a suitable counter II carried by a tube I2 extending from the counter wheel carriage MD The differential pressure wheel carriage likewise has an extension I8 to which are secured a group of cams indicated generally by numeral 14D and individu-- ally as 14a, 14b. The weight of these cams is partly counterbalanced by the counter II and associated mechanism, and a rod I5 secured to the counter wheel carriage having a spring I8 at its end secured in an eye screw I6 passing through the base biases the counter wheel downward with the required pressure against idler wheel 64. The counter II is driven directly from counter wheel 68D whch frictionally engages the top surface of the idler wheel 64. Movement of the differential pressure carriage 61D and difl'erential wheel BBB is limited to the left by the bracket 5| so that the differential wheel 88D cannot pass the center of idler disk 84, and movement to the right is limited by bracket 52 to prevent the roller 68D from being moved past the outer edge of idler disk 64.

Static and diflerential pen control The bracket 52 (Figures 1, 9 and 12) has a lateral extension 88 at the top thereof in which is journalled a shaft 8|. This shaft extends through the extension and through a flanged bushing 82 in the base on a spacing washer and its lower end is supported by one end of a spring member 88 having one end secured to the base. A differential pressure pen arm carriage 84D is pivoted about this shaft 8| at its lowerend and has an elongated hub 11 extending about the shaft 8| and through the bushing 82. The upper end of the'pen arm carriage 84D is secured to a sleeve 18 which extends along shaft 8| and is journalled in a bushing 18 in the extension 88 of bracket 52. A roller carrier 88D is suitably clamped to the sleeve I8 near its top and carries at its outer end a roller 88D pivoted to rotate freely on its axle 86'. The roller carrier 88D is biased tomaintain roller 86D in contact with the edge of one of the cams of group 14D by a spring which will be described hereinafter.

A static pressure pen carriage 818 is swivelly mounted aboutthe sleeve I8 and rests upon a suitable spacer hub I28 on carriage 84D. The static pressure pen carriage 818 has an upwardly extended hub 88 surrounding sleeve I8, and a link "S is suitably clamped to this hub at one end and has its other end bifurcated to form a guide 88. The roller carrier 85B is clamped to the shaft 8| amasss in any suitable manner to rotate therewith, and has an upright key 58 which fits between the bifurcated ends 88 of link 188. A spring 88 is secured to the side of link 18S, and a ball bearing 88 is interposed between the key 58 and spring 88 in a suitable recess in the spring for biasing the link 18S and extension roller carriage 85S together to take up slack at this joint. The carriage 858 has a cam roller SIS freely journalled at its end which rides over the edges of one of the cams in group 628 and which is maintained in contact therewith by a spring to be later described. The spacing of the cams in groups 625 and 14D and the width of the rollers SIS and 88D are such that the rollers can each contact at the same time only one cam of their respective groups. The static pen control arm 825 (Figure 1) and differential pen control arm 92D are pinned to suitable trunnlons 84 and 85 respectively Journalled in a suitable ball bearing assembly in the base I. Beneath the base an arm 96D (Figure 2) is suitably clamped on the trunnion 95 to rotate therewith as the lever 92D is shifted, and at its outer end is pivotally secured a bifurcated connecting rod 810. The trunnion 84 likewise has an arm 885 secured thereto; and at its outer end is pivotally secured the bifurcated connecting rod 888.

At the left end of the base as shown in Figure 1 (Figures 1, 9 and 12) a flanged hollow post I8I passes through a suitable opening therein, and is held in position in any suitable manner as by a nut I82 threaded on to a threaded reduced portion of the post adjacent the flange. A hollow shaft I858 is journalled within the post IM and at its lower end beneath the base has secured thereto in any suitable manner an arm IIGS to which the connecting rod 885 is pivotally secured at its outer end as indicated at I81. The length of the rod 888 can be adjusted in any suitable manner and in the preferred embodiment has a clevis I88 threaded on the end thereof and held against turning by a nut I88. The other end of the hollow shaft I858 which extends from the post I8I has secured thereto an arm 28, which in turn is pivoted to one end of a link 3, the other end of which is pivotally secured at II4 to the slidable carriage 558. A shaft IISD is journalled within the hollow shaft I858 and extends therefrom at both ends. At its lower end is suitably secured an arm I86D to which the connecting rod 81D is pivotally secured at its end as indicated at I II. The length of rod 81D can be adjusted in a similar manner as the length of rod 98S through a clevis I88 and nut I88. At the upper end of shaft IIID is secured an arm II8D pivotally connected at H8 to one end of a link I2I which at its other end is pivotally secured to the sliding carriage ID as indicated at I22.

The static. pen assembly I258 (Figures 1 and 17) comprises a flat adjustable supplemental arm I28 having a C-shaped enlarged portion I88 at its outer end in which is swivelled a pen holder I8IS havinga pen or stylus I82S secured thereto at its end. An arm or holder is' provided comprising two posts I88 and I 84 rigidly pinned together with a spacer I8I therebetween and having cylindrical ends I88 and I88 which fit into the holes I88 and I88 in the end of static pen carriage 818. The post I84 is reduced at I48 to serve as a spring, and has a segment or plate I secured thereto at its end. This plate'has a group/of holes therein indicated generally by the numeral I42 and individually as I42a, 2b, etc., adapted to be brought into registry with a similar tapered hole I43 in the arm I26, and a registry pin I44 passing through a hole I42 pins the arm- I26 and post I34 together. The plate I has a slot I45 therein, and a locking pin I46 passes through the slot into a threaded hole I in the arm I26 to lock the post I34 and arm I26 in adjusted position. The arm I26 has an arcuate cut out portion I48 which fits about the spacing hub I23 (Figure 12) in assembled position. By means of a screw I46 threaded into post I34 and bearing against post I33 a delicate adjustment is obtained as will hereinafter appear.

The differential pen assembly I25D (Figure 1) comprises two posts I21 and I28 rigidly secured together with a spacer I 39' between, and having similar cylindrical ends I35 and I36 which fit into the holes I31 and I38 in the end of differential pen carriage 84D. The post I28 is reduced at I29 to serve as a spring, and at its outer end is swivelled a pen holder I3ID having a pen or stylus I 32D secured thereto at its end. An adjustment screw I 50 threaded into post I28 and bearing against post I21 providesa similar accurate adjustment.

Operation to hollow shaft 158 extending through the post IOI in the base, and as arm II2S is secured to this shaft the swinging motion of arm 23 will bear a definite predetermined ratio to the swinging movement of control arm 928. This relation can be varied, if necessary, by adjusting the length of rod 998, or by using different length arms at 988 or 65. As arm II2S is connected to sliding carriage 558 by a link H3, the movement of control arm 928 will slide the carriage 55S back and forth on static pressure carriage rod 53, moving the cam group 628 therewith.

Let it be assumed for the present that the as the carriage and cams are reciprocated by the control arm 928 along the rod 53. As the roller SIS is kept in contact with the cam edge by a suitable spring the movement of the cam 628 will pivot theroller carrier 85S about shaft 8| and link 10S will pivot the static pen arm carrier 818 about the sleeve I8. By proper movement of control arm 923 the static pressure pen I32S can be caused to follow the static pressure curve on the chart as the chart is rotated with th chart plate.

The chart plate 33 and time disc 2|! are rotated synchronously by motor 3 in a predetermined relation through the reduction gearing in case 5,

line shaft I6 andgearing in frame 3|. As the operative manipulates the control arm 92S to cause the pen' I328 to follow its curve, the movement of carriage 55S will move the roller or wheel 56S varying distances from the center of time plate 26, and the roller 568 will be driven at varying speeds depending on the contour of the static pressure curve. .The movement of control arm 92D similarly shifts the'carriage 61D along its carriage rod- 54, through the arm 96!), arm 1061),

shaft II5Dand arm II8D, and through the cam group 14D, and roller 86D causes the roller carrier 89D secured to sleeve I8 and differential pen carrier 84D secured thereto to move in a path so that the differential pressure tracing pen I 32D follows the curve on the chart.

The instantaneous speed of the periphery of roller 565; will be some multiple K of the absolute pressure being registered at that instant by the tracing pen I32S, and the revolutions turned by the idler disc during any infinitesimal lapse of time may be expressed as the integral where p is the absolute static pressure, and K is a machine constant based on the ratio between actual revolutions of the idler disc representing the desired numerical value of the chart being calculated, and the revolutions of the chart. The revolutions turned by the idler disc 64 in any given length of time value represented on the chart be KTJF where K is the machine constant mentioned above, T is the time integral, and P is the average absolute pressure registered by the orifice meter pen, it being understood that the cam 62S guides the static pressure pen I328 so that the distance of roller 568 from the center of plate 2|] is proportional to the square root of the absolute pressure being traced by the pen. The peripheral speed of rl1er56S is transmitted to idler disc 64, and if a constant speed of idler disc 64 is assumed; in

other words, a constant pressure being assumed indicated by the static pressure pen I328, the differential roller 681) would have a peripheral speed which is some multiple C of its distance from the center of the idler disc. If the cam MD is a square root cam, such as a parabolic cam, this distance from the center of the idler disc will be some multiple of the square root of the position on the chart of pen I32D, and the revolutions turned by roller 68D would be the integral of the square root of the differential pressure, or

E f\ t But the idler disc 64 reproduces the integral of the square root of the static pressure curve in terms of revolutions, and roller 68D multiplies this integral by the integral of the square root of the differential pressure curve, thereby rendering a value in terms of revolutions known as the extension of the chart. This is expressed mathematically as -T P. D, r v where P is the integral of p and D is the integral of the differential pressure.

The stop mechanism Plate :3 (Figures and is provided with a downwardly projecting rim I5I in which a. multiplicity of slots I52 are accurately machined for the reception of a stop mechanism operating as,

spring I58 secured to the latch at one end in hole I58 and to shaft I6I at its other end. The stop member has a step I62 which is adapted to be engaged by an overhanging portion I63 of latch I 56. Shaft I6I extends through the depending portion of base I at one end, and its other end is journalled in a bearing member I64 swivelled upon the depending hub 28 of the frame 3|, and is held in adjusted position by a set screw (not shown).

Setting lever I65 is arranged to oscillate shaft I BI and an arm I61 thereon cooperates with proiections I68 and I68 on stem I54 for retracting the stop member I53. When so retracted the overhanging portion I63 of latch I56 engages the step I62 on the stop member I53 to hold the stop in retracted position.

The shaft I 6I has secured thereon an arm I15 to which is attached a flexible chain or cable I16 (Figures 9 and 10) which passes through a conduit I11 and up through the base where its other end is secured to one end of a rocker arm I18. The conduit I11 passes through ahexagonal head screw I18 threaded into the base which supports one end thereof, and its other end is held in the base between two hexagonal nuts HI and I12 threaded on the upturned threaded end of the conduit. The other end of rocker arm I18 is biased by the tension of a spring I18 secured in an eye screw I88, and the tension of this spring transmitted through rocker arm I18 and cable I16 attached to arm I15 tends to rotate shaft I6I counter clockwise. The arm I61 secured to shaft I6I is therefore kept pressed against the upper pin I68on the stem I54 of stop member I53 when this member is in depressed position and biases stop member I53 upward.

The rocker arm I18 is secured to one end of a rock shaft I8I (Figure 1) which is journalled in brackets I82. This shaft-extends along the face of idler or differential wheel 64 and is rotatably supported at its other'end in a bracket I83. Secured to this shaft is a brake member I84 having a rubber or similar edge I85 which is positioned between counter wheel 68D and idler disc 64 and normally during operation is out of contact therewith. In stopped position brake member I84 raises counter wheel 68D out of contact with idler disc 64, the rim of counter wheel 68D being in frictional contact with the rubber edge I85.

The shaft 32 (Figure has a flange I85 integral therewith, and a swivel plate I 86 is swivelly located thereon in spaced relation to the chart plate 33 and base I. The springstop member I83 is secured thereto in a recess at one end, in any suitable manner and has a finger piece I84 whereby it may be depressed. A hole I81 in the base I is provided to permit access thereto for repair or replacement when required. Latch I58 has a projecting portion I8I adapted to be engaged by a projecting striker I82 on spring stop member I83. The spring member I83 is of such width as to fit into any one of the uniform slots I52.

The operation of the brake mechanism is as follows: When a chart has been positioned on the rubber covered chart plate 33 the finger piece which is positioned directly over the stop thember I53 is depressed by the operative thereby depressing the stop-member I53 against the bias of spring I18 transmitted through rocker arm I18, chain I16, arm I15, shaft I6I and arm I61 coacting with pin I68. The spring I58 pivots the latch member I56 towards shaft I6I and causes the overhanging portion I63 thereof to engage step I62 of stop member I53'to hold it in retracted position when spring member I83 18 released.

Release of finger piece I84 permits spring member I83 to enter one of the slots I52. The lever I 65 provides an auxiliary means for depressing the stop member, for by rocking this lever clockwise the arm I61 on shaft I6I engages pin I68 and depresses the stop member I53.

The spring stop member I83 being set in the proper recess I52, the tracing points I32S and I32D are positioned on their respective curves by the operative and the motor 3 is started. The chart plate 33 is driven through line shaft I6 and friction couplings 36, 31, and as the operative traces over the curves on the chart the proper values will be recorded in counter II as previously described. The member I83 does not leave the notch I52 but rotates with platen 33, and when the platen has made one complete revolution the depending portion I82 of stop lever I83 will engage the projection I8I of latch I56 and rock it about its pivot I51 thereby releasing overhanging portion I63 from step I52 of stop member I53. Because of the biasing action of spring I18 tending to raise stop member I53 the member I53 will spring into a notch I52 and stop rotation of the platen at exactly one revolution. Simultaneously therewith the pull of spring I 18 on rocker arm I18 rocks shaft I8I causing the rubber edge I85 of brake member I84 to engage counter wheel 68D and lift it and the carriage 61D out of contact. with the idler disc 64. The rubber edge I85 instantly stops the rotation of wheel 68D and thereby stops operation of counter H at exactly the proper position with reference to the curve on the chart. The motor 3 may not be stopped instantly by the operator, and its momentum and the inertia of the moving driving gearing would throw a severe strain on the mechanism. However, be 'ause of the friction drive '36, 31 in the platen drive assembly, and the friction coupling 1, 6 between the motor shaft 6 and wbrm shaft 8, these parts may continue to rotate without danger of breakage until the operative stops the motor.

As usually constructed, the orifice meter charts are so arranged that a complete revolution thereof corresponds to 24 hours of use. If for any reason, it is desired to integrate a smaller portion of the chart, such as for example, four hours, the stop member I53 is depressed as previously described, and the spring stop member I 83 is moved back sixteen notches, each notch corresponding to one-quarter hour, and the tracing points are positioned to trace the portion of the curve to be integrated. The motor is operated as before to rotate the platen 33. When the tracing points have reached the end of the desired period, the spring stop lever I83 will have returned to zero position and will rock latch I56 as previously described to stop the mechanism.

Examples of chart types In Figure 16 is shown a fragmentary view of three types of orifice meter charts superposed to bring out the characteristic differences in the charts. For convenience these charts are indicated as type A, type W and type F. on each chart the extreme inner circle represents atmospheric pressure, which generally is taken as 14.4

pounds per square inch, and the extreme outer circles of the charts are usually divided into ten W and F these arcs are struck on separate centers not equally distant from the center of the chart and therefore do not coincide, and further the angles subtended by the arcs are not-equal. Considering charts A. and W, the angle subtended by the arcs likewise are not equal, nor are the arcs coincident. The centers of these arcs represent the centers about which the recording pens of the several: orifice meters swing in recording the static pressure and diiferential pressure curves on the charts.

The apparatus. so far as has been described is intended for operation on chart type W. The: center about which the pens i328 and |32D are pivoted in tracing their respective curves corresponds to the center of the radial curve of chart type W, so that with the chart at rest the tracing pens would describe a radial arc coincident with the radial arcs on the chart. In order to adapt the apparatus for integrating chart types A and F it is necessary to transpose the center of pen motion to coincide with the centers of the radial arcs of said chart types, and further if it is desired to use the same cam for integrating chart types A and F as is used for integrating chart type W it is necessary that a direct proportional I motion be transmitted from the cams to the respective tracing pens.

The apparatus by which this is accomplished now will be described.

Tracing pen assembly for type K charts Referring to Figures 1, 14 and 15, it will be seen that a static pressure and differential pressure tracing assembly indicated generally by the numeral 20|F is located adjacent the bracket '52 about which carriages 81S and 84D pivot, and has static pressure and differential pressure pen carriages 2028 and 202D respectively pivoted about an axis 203. Referring to Figure 12 it will be seen that the differential pressure carriage 84D for the type W chart has a depending hub 11 and. a segmental gear 205D is suitably secured thereto beneath the base I. The shaft 8| also depends beneath the base and has secured there adjacent its lower end a segmental gear 205s suitably secured thereto. These segmental gears serve to transmit the swinging motion imparted to the' cam roller arms by movement of the cams to the differential pressure pen carriage 202D and static pen carriage 2028 by means presently to be described for tracing the curves on a type F chart.

Referring to Figures 14 and 15 it will be seen that the assembly 20 IF comprises an upper plate 206 and a lower offset plate 201 having a corner post 208 integral therewith to form a unitary structure. A suitable ball bearing assembly 209 is secured to pivot 203 and differential pen carrier 202D is pivoted to swing freely thereabout. This carrier has a cutout portion at its outer end for receiving a differential pen arm pivoted therein. At its other end adjacent its pivot is formed integral therewith a segmental gear 2| ID 214 having one end secured to a projecting eye on gear segment 2| ID and its other end secured to an eye on gear segment 2I2D takes up any backlash or play in the meshing of. these gears. The gear segment 2I2D has a hub 2l5 extending downwardly therefrom to which is suitably clamped a differential pen carrier driven crank 2l6D. v

The static pressure pen carriage 2025 is com' posed of two separate parts, one part being an arm 2 l I having a cutout portion at its end adapted to receive a suitable pen arm, and having a bore at its other end fitted about a suitable ball bearing assembly 220 on axis 203. The other portion of the static pen carriage comprises an arm 218 having a segmental gear 2I9S integral therewith at one end, and having a suitable slotted flattened portion 22l at its other end. The two arms constituting the static pen carriage 2028 are mounted upon the suitable ball bearing assembly 220 to rotate about axis 203, and are adapted to be pinned together for simultaneous motion by a knurled clamping screw 222 pass-' ing through the arcuate slot in flat portion 224 and threaded into arm 2 IT. The segmental gear 2|9S is meshed with a similar segmental gear 223s having a spacing hub 22l by which it is pinned to the shaft 2l3 to rotate therewith. A static pressure carriage driven crank 224s also is pinned to the shaft 2I3 to rotate therewith. A spring 225 similar to spring 2 takes up the backlash between gear segments 2l9S and 223s. The swinging movements of the static pressure carriage 202s and differential pressure carriage 202D are limited by stop pins 226 and 22'! passing through the upper and lower plates 206 and 201 and secured therein. It will be apparent from the foregoing description that by swinging the driven cranks 216D and 2248 about their respective pivots the carriages 202D and 202$ likewise are swung about the pivot 203.

Referring to Figure'12, through a suitable hole in the base I is passed a threaded bushing 230 held in place by a nut 23l threaded thereon. A segmental gear 232D has a hub 233 which passes through a suitable hole in the bushing 230, and

at its upper end has suitably clamped thereto a differential pen carriage driving crank 234D. The driving crank 234D is bifurcated at its outer end as indicated at 235 (Figure 1) to receive the depending end of the driven crank 2IBD which is received between a leaf spring 236 suitably secured to the driving crank as by peening thereto, and a knurled locking screw 23'! is threaded into one of the bifurcations. The spring prevents play in the parts at this point, and the screw 23'! provides an accurate zero adjustment as will hereinafter appear. A hollow sleeve 239 is journalled within a suitable aperture in the gear hub 233 and is journalled at its lower end in a bracket 238. A thick segmental gear 24|S is clamped to sleeve 239 adjacent its lower end to rotate therewith. At the upper end of the hollow sleeve 239 is clamped a static pressure carriage driving crank was similar in construction to the driving crank 234D and having a similar bifurcation 239 and zero adjusting screw 240 operating in conjunction with a leaf spring similar to leaf spring 236.

.The base is provided with a solid post 245 and a hollow threaded post 216, and in securing the assembly 20IF thereto, thereduced portion of post 245 is fitted into hole 241, and the reduced portion of post 246 into hole 244,.and the assembly is clamped in place by a knurled clamping.

into the end. The shaft 2 l3 fits loosely into hollow sleeve 239. The static pressure carriage driven crank 224s and the differential pressure carriage driven crank 2l6D are suitably located with their depending ends in the bifurcations of their respective driving cranks 242s and 234D respectively.

Operation of type F chart tracing means From the foregoing description it will be seen that upon operation of the control arms 92S and 92D the cam carriages S and 61D will be shifted as previously described and will swivel pen carriages 81S and 84D about the shaft 8| as a pivot. The swinging movement of carriage 81S is transmitted to the shaft 8| by roller carrier 85S and shaft 8i has the segmental gear 2058 at its end. The gear 205s meshing with the wide gear 24! S will oscillate the sleeve 239 and driving crank 2425 clamped thereto. The driving crank 242s drives the driven crank was which is pinned to the shaft H3, and thus drives the segment gear 223s likewise pinned to shaft H3, and which meshes with the gear segment 2IBS on arm H8 and through the clamping screw 222 drives the pen carrier arm 202s. Oscillation of carriage 84D oscillates segmental gear 205D secured to the hub I1 which in turn drives segmental gear 232D 'and differential pen carriage driving crank 234D clamped to the hub 233. The driving crank 234D engages the depending end of driven crank 2|6D and thereby oscillates segmental gear 2I2D through the hub 2 I 5 to which the crank is secured. Gear 2l2D engages gear 2| ID integral with the end of the differential pen carriage 202D and oscillates the same about its pivot. The proper proportional movement between the lineal movement, of the cam carriages and the static pressure pen carriage 202s and differential pressure pen carriage 202D of the assembly 20IF is maintained by proper selection of the radii of the pairs of gears 205D, 232D, and 205s, 241s, so that the movement of the tracing pens on this assembly is always linea'lly proportional to the movement of the tracing pens on the type W chart tracing assembly. Therefore the corresponding static pressure cam and differential pressure cam used for the integration of the curves of the type W chart curves may be used for integrating the curves on-a type R chart.

Tracing pen assembly for type A charts Referring to Figure 16, it will be seen that the radial curves of chart A are made from a point at the right as a center. The pen assembly for integrating type A charts therefore is located at the right'end of the machine. Referring to Figures 1 and 12, a bushing 25l is pressed into a suitable hole in the base I, and a driving dog or crank 254D has an elongated hollow hub 252D which is journalled in said bushing, this dog having a bifurcated end 213. Thedriving dog 2548 has a solid hub 253$ which is journalled in the hollow ,hub 252D, the end of hub 253s extending below the end of hub 252D and being journalled in a bracket 255 secured to the underside of the base I. An extension arm 258D is "clamped to the end of hollow hub 252D, and a similar extension arm 2515 is clamped to the solid hub 253s adjacent its end. The gear 232D has adjustably secured thereon a radial extension 258D, (Figure 2 which is slotted adjacent its inner end and is clamped to the gear by suitable set screws so as to be radially adjustable to vary the effective radius thereof. A connecting rod 259D (Figures 2 and 12) is bifurcated at its end, and is pinned to the outer end of extension 258D by a clevis pin 26L Its other end is threaded intoa spanning rod 262D and locked against adjustment by a lock nut. A connecting rod 263D is similarly threaded into the other end of spanner rod 262D and has its bifurcated end pinned by a clevis pin 264 to the extension arm 256D. The biasing action of a spring 285 secured at one end to the base I and at its other to extension 256D is transmitted through this linkage and keeps roller 86D always in contact with the cam edge of cam group "D. A similar extension 2658 is secured in a similar manner to gear is, and a connecting rod 261s bifurcated at one end is pinned by a clevis pin 268 thereto, theother end of connecting rod 2618 being adjustably threaded into spanner 2698. A connecting rod 21 IS is similarly threaded into the other end of spanner rod 269$ and has its bifurcated end pinned by a clevis pin 212 to the extension arm 251$ secured on hub 2538. A spring 210 similarly keeps the roller SIS against the edges of cam group 625. Therefore, it will be seen that the swinging movement of segmental gears 241s and 232D,v which controls movement 211A is mounted. The assembly 211A (Figures'l and 13) comprises a suitable bracket having an overhanging portion 218 in which is secured a pin 279 having ball bearing assemblies 28! and 282 mounted thereon. The differential pressure pen carrier 283D has a cutout portion at its outer end to pivotally receive the differential pressure pen arm, and has a backwardly and downwardly extending driven crank 284D integral therewith. The static pressure pencarriage 2838 is composed of two parts; a longer stylus arm .286 having a cutout portion at its end to swivelly receive the differential pressure pen arm and a shorter supplemental arm or segment 28! having a flattened portion 288 at its outer end with a slot 289 therein, and a knurled screw 2! clamps the upper arm 28! to the lower one 286. This arm 28! likewise has a rearwardly extending and downwardly depending driven crank 292S. The driven cranks 284D and 292s are adapted to be received in the bifurcations of the driving dogs 254D and 254s respectively from which they are driven.

Operation of type A chart tracing means As previously described in connection with the operation of the tracing pens for the type W chart, the operation of the control arms 92S and 82D reciprocates the cam carriages 55S and 57D respectively, which reciprocates the cam groups 523 and 14D respectively secured thereon.

the type W are to be integrated the assemblies ZIIF and 211A are removed bodily so as to leave the proper free space for operation of the pen arms 132D and [328.

When charts of the type F are to be integrated the pen arm assemblies I25D and i258 are removed and the assembly 20IF is located in its proper place and secured to the base by the clamping screw 243. The depending ends of driven cranks 2 IGD and 2248 fit into the bifurcations 235 and 239', and are held to prevent lost motion by the leaf springs 236 and screws 23! and 240. Upon operation of the control arms 92S and 92D the cam carriages 55S and MD are reciprocated as before, and the oscillations of roller carriers S and 89D are transmitted through the shaft 8| and sleeve 11 respectively to the segmental gears 205s and 205D which cooperate with segmental gears is and 232D to cause a proportional swinging of the driving cranks 2423 and 2341). This motion is transmitted to the pen arms 202$ and 202D through the driven cranks 2248 and 2 I 6D and segmental gearing in the assembly 20|F to cause the pens mounted therein to follow the curves on the chart as the chart is rotated. The integrating operation performed by the integrating discs and wheels will be the same for charts of this type as for charts type W, and it will be observed that because of the proper proportioning of the swinging movement of pen arms 2112s and 202D to the swinging movement of the carriages 81S and D the same carn can be employed in integrating the type W and type F charts.

When it a desired to integrate type A charts the assembly 2lliF is removed and the assembly 211A is located in place on the posts 215 and 216 and is clamped in place by a suitable clamping screw 2". When assembled therearwardly depending driven cranks 284D and 252s are located in the bifurcations 273 and 2," of the driving cranks 254D and 2548 respectively. The oscillating -motion of segmental gear. 2H8 is transmitted through the connecting extension 2658 and connecting rod 261s pivoted thereto, and through spanner 2698 and connecting rod 2'IIS to arm 2518 which is clamped to the hub of driving crank 254s. The oscillating motion of segmental gear 232D is transmitted through extension 258D and connecting rod 259D pivoted thereto, spanner 262D and connecting rod 253D, to the arm-256D secured to the hollow hub of driving crank 254D. By adjusting the lengths of extensions 258D and 2653 a proper proportional movement can be secured between the oscillating motion of gears 2H8, 232D, and driving cranks 2548 and 254i), and consequently between the cam groups 628, D and the driving cranks 2548, 25lD. Therefore, the same cams can be used in integrating type A charts.

Calibrating and adjusting In the original calibration of the machine it is necessary to determine proper ratios to be allowed between revolutions allowed for registering static pressure values, and for differential pressure values. The ratios are set as a matter of convenience, and are calculated from the multipiier decided on for the machine. Preferably,

the machine is so designed that the multiplier is 1.0 when integrating a lbs. static pressure chart with atmospheric pressure taken as 14.4 lbs. per square inch. Having determined a maximum number of revolutions of idler disk 64 to be allowed for the maximum pressure shown on the carriage is now adjusted to the,point which will give the predetermined revolution value for any 1 particular absolute pressure value. Cam 628 is mounted on the carriage, the pen is placed on the particular pressure which is being calculated, and a punch mark is placed on the cam to indicate the center of the cam roller, which will give the position of the contour of the cam i'or this pressure. After a large number of points on the cam have been determined in this manner the curve may be scribed on the cam, and the cam cut to shape.

Having completed the static cam the static pressure pen is set and locked with the carriage in position on a known value of static pressure, then with this value of static known, the value of the extension desired can be computed for each of a number of values of differential, and the process of laying but the differential cam carried outin the same manner in which the static cam was laid out.

After the cams 62a and 14a are calibrated for the type W charts themovement between the type W assembly and type F assembly must be adjusted so that the pens of the respective assemblies are in accord. The pen carriers i258 and i25D are removed, and a type F chart is placed upon the platen. By setting the cam carriages 55S and 61D at their respective left hand limits of movement, which would bring the pens I32D and i328 at the atmospheric pressure circle of a type W chart were they in place, the pens of the type F assembly likewise should lie on the atmospheric pressure circle. If they do not, the gear segments 205D and 205s are released and rotated relative to the-hub l1 and shaft 8| until the pens are in proper position, and the gears are then firmly clamped in place. The gear ratios oi pairs of gears 205D, 232D and 205$, 24 IS is such that when the pens of the type F assembly are at the outer circle of the type F chart the pens of the type W assembly likewise would lie on the outer circle of the type W chart.-

In the case of the type A pen assemblies the same procedure is followed. If the movement of the pens of this amembly is properly proportioned to the movement of the pens of the, type W assembly, but the atmospheric pressure positions do not correspond, the arms 256D and 2518 can be rotated relative to the driving dogs 254D and 254s to bring the pens to their proper position, or, the lengths of connecting rods 259D and 2618 can be adjusted. To adJust the proper proportioning of the pen movement the arms 258D and 2658 can be adjusted radially on their respective gears whereby the correct proportioning between these arms and arms 266D and 2513 respectively is accomplished.

. Occasionally the pen arms may be sprung in mishandling the machine, and provision is made for adjusting the pens to :15 proper zero position in such instances. Referr g to Figure 1, it will be seen that the diiierential pressure pen carrier I25D has two parts one of which numbered I2! is reduced to provide a spring action, and thi: part carries the tracing pen I 320 at its outer end The other part I21 or this arm is rigid. when the control arm 92D is placed in its extreme position the tracing pen I32D should coincide with the zero circle. If it does not, the adjusting screw I is rotated to force the posts I21 and I28 further apart or closer together as is required to shift the tracing pen without affecting any movement of the roller 86D in relation to the cam groups MD. The static pressure pen I323 likewise can be adjusted by turning the knurled screw I49 to set the pen at the proper zero position.

Provision is made for integrating charts ofvarious static pressure ranges. Referring to Figure 16, it will be seen that the space between the extreme inner and outer circles of these charts hereinafter referred to as the pen travel, represents a static pressure of 100 pounds gauge, or 6.94 atmospheres. When charts are employed for other static pressures the diameter of the inner circle is the same for a given type chart, and the distances between the inner and outer circle remains the same, but instead of this distance representing 6.94 atmospheres it would represent some other given static pressure, as for'example 500 pounds or 34.72 atmospheres. The same pen travel in one case will represent 6.94 atmospheres, and in the other case will represent 34.72 atmospheres. Because the inner circle represents atmospheric pressure and the laws relating to behavior of gases are based upon the absolute pressure of the gases, it will be seen that the absolute zero of a 500 pound static pressure chart of the same type would not be the same radial distance from the center as the absolute zero for a 100 pounds static pressure chart. The square root law of the cam is based on atmospheres. Therefore fora 500 pound pressure range chart an ad- Justment is provided such that when the stylus point is at the atmospheric pressure circle the roller 9IS is at a point on the cam equivalent to or 5 atmospheres.

For this adjustment, the flattened portion I of the pen arm I255 has a plurality of holes I42 drilled therethrough, these holes being accurately positioned and marked to indicate different static pressure ranges. To adjust the pen arm for a different static pressure range it is necessary only to release locking screw I46, remove the tapered pin I44 from one of these holes I42, and bring the desired hole H20 in registry with the single hole I43 in the arm I26 and reinsert the tapered pin I44 and tighten locking screw I46. The static pressure tracing pen thereby will be properly zeroed in relation to the cam for integrating a different static pressure range chart. It will be noted that the pen assembly I258 is. made up of two separate and relatively movable parts, and the movement of parts I26 and I34 relative to each other by knurled screw l4l'likewise shifts the relation of roller SIS to ,the cam groups 628. However, the static pressure range adjustment differs from knurled screw zero adjustment in that the latter is only to make the stylus point coincide with the inner chart circle when the cam is ata'ine end of its travel, and therefore does not shift the relation of roller SIS to the cam edqe The adjustmenthif the pen carrier 2028 for various static pressure ranges is the same as in the case of the pen arms for the type W'chart. The clamping screw 222 is released and pin 22I is removed. Arm 2I'I then can be rotated while arm 2I8 remains fixed by crank 224$ engaging dog 242S, and when the proper holes are brought into registry pin 22I is reinserted and clamping screw 222 is tightened. The zeroing adjustment for the pen arms 202s and 202D is accomplished by proper adjustment of knurled screws 231 and 240, this adjustment being intended for compensating for accidental springing of the pen arms after the mechanism has been adjusted. To adjust the pens in assembly 211A (Figures 1 and 13) for various static pressure range charts, the clamping screw 29I is released and pin I44 is removed thereby permitting arm 286 which carries the pen to be rotated while arm 28! remains held by crank 292$ engaging dog 254$. Arm 288 is rotated to bring the proper hole in flat portion 288 into registry with hole I43. The pin I44 is then reinserted, and clamping screw 29I is tightened to clamp arms 288 and 281 together..

Multiple cam mechanisms The apparatus so far described is designed to integrate the curves on various types of charts referred to as types W, F and A, all of which have a uniform division of the space between the extreme inner and outer circles, and in integrating such charts the same static pressure cam is used in integrating the various static pressure curves, and the same differential pressure cam is used in integrating the various differential pressure curves. The charts illustrated in Figure 16 are known as uniform charts, and the law of operation of the orifice meter pen which traces the curves on these charts is such that a direct proportion exists between the pressure and the radial movement of the recording pen. Some orifice meters do not have the recording pen operating at a uniform radial ratio to the pressure, and instead have the chart marked off by nonuniform spaces to compensate for this deviation. Such charts are known as non-uniform charts and a different pair of static pressure and differential pressure cams on the carriages are required for integrating charts of this type. Still another type of chart encountered in practice measures vacuum as well as positive pressure, and a separate static pressure cam is required in integrating this type of chart.

The cam carriages S and MD are equipped with a plurality of cams for integrating these types of charts as well as othertypes that may be found in practice, .and a mechanism is provided forshi-fting thelrelation between the individualc'ams andthe cam rollers adapted to coact therewith. This mechanism will now be described. Referring to Figures 9 and 12, the roller carrier 855 is clamped to the shaft 8i, while the ."roller carrier 89D is clamped to the sleeve I8 .in which the shaft BI is freely rotatable and longitudinally slidable. By vertically shifting the shaft'8i the roller carrier 858 is vertically shifted bringing the roller SIS into working contact with the edge of any desired one of the cams constituting group 628; The mechanism for shifting the carriage comprises an eccentric 305 mounted upon a shaft 308 and adapted to bear against the spring 83 where it bears against the lower end of shaft BI. The bracket 52 has a depending post 301 passing through a suitable hole in the base, and this post has a hole 308 adjacent its lower end in which the shaft 306 is journalled, the movement of the shaft being limited in one direction by the collar 3| I suitably secured thereto, and being limited in the opposite direction by a collar 3I2. A ratchet wheel 3| 3 is suitably secured to the shaft 306 and has a plurality of spring pawl 3i! suitably secured to the bottom of the base for holding the shaft 306 and eccentric 305 in fixed position. The shaft 306 can be rotated by the operative by means of an operating arm 3|6 having a knurled handle and pointer 3H for cooperating with indiceson the plate 3i3 secured in a recess on the base. It will be seen that the weight of the shaft 3| is partially supported by the spring 33. At the top adjacent bracket 52 'is located a coil spring 3l9 within the hollow sleeve 18, this spring being retained by the plate 32f secured by screws or other suitable means to the bracket 52. The other end of spring 3!!! coacts with a thrust disc 322 and ball 323 resting on the upper end of shaft 8!, whereby the shaftis urged downwardly, the springs 33 and 319 being suitably balanced. An annular groove 324 is formed in the shaft -8i adjacent its upper end for a purpose to be later described.

By rotation of shaft 303 the eccentric 335 is rotated, and as it bears against spring 33 at the lower end of shaft II the various positions of the eccentric will shift the shaft 3| vertically, and with it the roller carrier 36S and roller SIS secured thereto, to various positions predetermined by the spacing of the ratchet teeth 3" in disc 3", and the shaft ill will be held in such position by coaction of spring pawl 3!.5 and ratchet teeth 3l4. The ratchet teeth 3 are so spaced as to provide that the roller SIS and its carriage is shifted vertically a distance equal to the width 'of one cam for each tooth whereby any one of the four static pressure cams shown may be contacted at one time by roller SISQn integrating the corresponding type of chart.

The roller carrier 33D is not vertically movable. However, the roller 36D may be vertically shifted by the following means. The roller "D is rotatable on a pivot pin 33', suitable ball bearings being interposed to eliminate friction, and the pivot pin 36' has adjacent its upper end a flange 325 to which abent wire 323 is secured. A spring 326 is interposed between the flange 325 and the top of the carrier 33D to bias the pin 36' upward. A rocker structure 321 has depending arms 323 swivelly secured to the sides of roller carrier 39D,

and has a spherical bearing member 33l at its end bearing upon the flange 32! of the pin 36'.

The wire 323 coacts with a slot 333 in the rocker 321 to prevent rotation of the pin 36'. A rod 334 is threadedly locked in adjusted position to the rocker 321, and its other end 332 passes through a suitable hole in the roller carriage 39D and sleeve 13, and bears against the surface of shaft II, the spring 323 biasing the end "I upward and forcing the end 332 of rod 334 against the surface of the shaft 3!;

when the shaft 3i is shifted vertically upward to the first notch in ratchet 3 the biasing action of spring 323 urges the end 332' of rod 334 into the groove 324 thereby permitting the .axis 36' and roller 33D rotatable thereon to be shifted vertically. upward and contact the edge of cam 14b. At the same time the roller carrier .358 will be shifted upward causing the roller SIS to contact with edge of'cam 62b. In this position the mechanism is in proper adjustment for integrating a nonuniform type of chart not speciile cally described herein. I

In the non-uniform type of chart a special cam must be employed for the static pressure curve as well as for the differential pressure curve and the cams 2b and 14b therefore may be referred to as non-uniform cams. However, on the vacuum-pressure type of chart heretofore mentioned a uniform differential pressure cam can be employed, and it is necessary only that a. different static pressure cam indicated as 620 be used. Therefore it is necessary that the roller carrier 855 be shiftedfor cooperation between roller 9IS and cam 620, while the roller 86D be shifted back to cooperatewith uniform cam 14a. When the shaft 305 is rotated to the next notch the carriage 85S is shifted upward causing roller SIS to contact cam 820 while the end 332 of rod 334 is forced out of groove 224 thereby pressing pin 86' downward to cause roller 86D to contact cam 14a.

Upon further upward shifting of the shaft 8i a distance represented by the fourth notch 3l4 the roller SIS is brought into operative contact with the upper cam 62d, but the rod 334 remains in unchanged position in contact with the surface of the shaft 8|, and therefore the roller BBB is not shifted but remains in contact with the edge of cam 14a for integrating another type of chart.

In each case the integration of the curves on the various charts is performed exactly as previously described, the operative manipulating the control arms 92S and 92D to shift the cam groups 628 and 14D, and thereby cause the tracing pensto follow the curves on the chart.

In the modification shown in Figures 18, 19 and. 20, a different type of linkage is employed for transmitting motion from the type W tracing point center. to the type F tracing point center. In this modification wherein corresponding parts are indicated by the same reference characters hereinbefore used, the pen carriages 81S and 84D have extensions 34|S and 342D respectively which have the bifurcated links 3438 and 344D pivotally secured thereto.' The type F pen assembly, indicated generally by the numeral 3451 comprises two segmental gears 346s and 341D to which are pivoted .the links 3438 and 344D respectively. The segmental gears 3468 and 341D are suitably pivoted on anti-friction bearings about a pivot 349 held in place by a clamping screw 360 in a bracket 348, and coact with segmental gears 35iS" and 352D integral with the static pressure pen assemblies 353$ and differential pen arm 354D respectively. The pen assemblies 353$ and 354D are substantially the same in construction as assemblies 202s and 202D respectively.

A flanged .bushing 350 is located in a suitable hollow post on the base i, and a hollow shaft 355D extends therethrough. The gear segment 341D is pinned to the upper end of hollow shaft 355D, and an arm 356D is secured to the bottom thereof, said arm -having a slotted radially adjustable portion secured thereto by set screws or similar means. A solid shaft 351$ extends through hollow shaft 355D, and .has the gear segment 346s pinned thereto, an arm 3588 being secured'to the lower end of this shaft. Ann 3588 is similar in construction to arm 356D. The motion of gears 3468 and 341D is transmitted through the arms 3535 and 353D to the connecting links 3ND and 3598 respectively pivoted thereto, to the type A chart pen assembly. The springs 362 and 333'are secured at one end to post 364 and at their other ends to gears 35IS and 352D respectively for taking up backlash in the gear pairs 346$, 35|S and 341D, 352D.

A bushing 365 is located at the right end 01 the base I, and a driving dog 366D having a hollow hub 361D isjournalled therein. An arm 3531] is suitably pinned to the hub 361D and the other end of link 36ID is pivotally secured thereto. The driving dog 3698 has a solid hub 31 IS passing through the hub 361D, and at its lower end is pinned an arm 312s to which the other end of link 359s is pivotally secured. It will be apparent, therefore, that the driving dogs 366D and 3698 are operated from the segmental gears 341D and 3468, which in turn are operated from carriages 87S and 84D.

The pen assembly 312A comprises a hollow bushing'3'l3D having a driven crank 314D integral therewith, and a differential pen carrier 315D at its upper end integral therewith. The static pen assembly 3168 is composed of two arms, an upper arm 311 pinned to the shaft 318 which extends through bushing 313D and partially through hub S'HS, and a lower arm 319 swivelled thereabout. A driven crank is is pinned to the shaft 318 to rotate therewith. The ends of driven cranks 38IS and 314D fit into the bifurcations of driving dogs 3698 and 366D from which they are driven.

In this modification it will be apparent that the motion of the type W pen carriers is transmitted by pivoted links of fixed length, instead of by gears, to the type F pen assembly, and therefore is not directly proportional, and the armate motion of the pen carriers of the type F assembly will be transmitted proportionately substantially as previously described to the type A assembly. The pair of uniform cams 62a and 14a are employed in integrating type W charts. Because the motion of the type F tracing pens and type A tracing pens are not proportional to the motion of the type W tracing pens. a separate pair of uniform cams 62c and He are employed in integrating the latter charts, said cams being of proper shape to compensate for the actual proportional motion. The mecha nism for shifting the cam rollers 38|D and 3828 is substantially as previously described, the ratchet disc 383 having only two notches 384 and 385. Upon rotation of shaft 306 to bring the spring pawl 3I5 into registry with notch 385 the cam roller 3828 will be brought into contact with cam 62c, and cam roller "ID will be brought into contact with cam He.

The integration of charts is carried out on this modification as previously described. The assembly 345E can be removed when not in use by removing the bracket 8 which is held clamped on the case i by the clamping screw 360. This bracket carries the gears ISIS and 3521) integral with the static pressure curve tracing pen arm 3538 and differential pressure curve tracing pen arm 354D, so. that the whole assembly 5F can be removed or replaced as a unit, the gears 351s and 352D being properly meshed with gears 3488 and 341D upon replacement of the assembly.

In Figure 22 is shown a preferred embodiment of a divider 386 for correcting constant errors in the orifice meter charts which may be due to loss of mercury, or permanent distortion of the recording pen arm. The divider comprises a bifurcated spring member having the spring arms Ill and 388, the former terminating in a point 389 on a level with the point 390 of pen 39L The other arm "8 has a sleeve 392 fitting closely over the shank of the pen "I and a set screw 3 clamps the divider to the pen. The distance between the points 389 and 390 can be adjusted by turning the adjusting nut 394 on screw 39 5.

In operation, the divider is placed upon a tracing pen on the integrator, and the distance between the pcints 385 and 390 is adjusted to the desired distance. In integrating a curve on the chart the curve is traced by the point 389 instead of by the pen, and the pen records on the chart a legible curve representing the true compensation for the orifice meter error at the same time as the integration takes place.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not descriptive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is'claimed and desired to be secured by United States Letters Patent is:

1. A machine for integrating charts comprising chart supporting means, counting means, means for actuating said counting means, tracing means, means connecting said actuating and tracing means for causing variations in the rate of actuation of. said counting means in accordance with the operation of said tracing means, means for varying the locus of said tracing means to predetermined positions, said tracing means being connected in its varied positions to said connecting means.

2. A machine for integrating charts comprising chart advancing means adapted to receive a chart having a curve thereon to be integrated, a

stylus arm carrying a stylus and operating from a fixed pivot for following the curve to be integrated, a counter, means variably driving said counter in accordance with the movement of said stylus to register on said counter the integral of the square root of said curve, means to receive a second stylus arm operating from a second fixed pivot for use in integrating other types of charts, and a proportional motion transmission means operatively connecting said stylus arm and said last named means for maintaining the angular motion of said arms proportional.

3. A machine for integrating charts comprising chart advancing means adapted to receive a chart having a curve thereon to be integrated, means operating from a fixed pivot and adapted to operate a stylus for following the curve to be integrated, a counter, counter driving means variably operated in accordance with the movement of said stylus operating means to register on said counter the integral of the square root of said curve, means operating from a second fixed point adapted to operate a second stylus for tracing a curve on other types of charts, and means adapted to connect said second stylus operating means with said counter driving means, to register on said counter the integral of the square root oi the curve on said other types of charts.

a. .A machine for integrating charts comprising chart advancing means adapted to receive a chart having curves thereon to be integrated, means operating from a fixed pivot through a limited arc and adapted to operate a stylus for following the curve to be integrated, a counter, means variably driving said counter in accordance with the movement of said stylus operating means to register on said counter the integral of the square root of said curve, means operating from a fixed pivot through a different limited are adapted to operate a second stylus for use in integrating other types of charts, and motion transmission I means operatively connecting said styli operating means for maintaining the angular motion thereof proportional in the ratio of their respective arcs of movement.

5. A machine for integrating charts comprising chart advancing means adapted to receive a chart having curves thereon to be integrated, means operating from a fixed pivot through a limited arc and adapted to} operate a stylus for following the ,curve to be integrated, a counter, means variably driving said counter in accordance with the movement of said stylus operating means to register on said counter the integral of. the square root of said curve, means operating through a different limited arc of reverse curvature from a difierent fixed pivot adapted to operate a second stylus for use in integrating other types of charts, and motion transmission means operatively connecting said styli operatingmeans for maintaining the angular motion thereof proportional in the ratio of their respective arcs of movement.

6. A machine for integrating charts comprising chart advancing means adapted to receive a chart having a curve thereon to be integrated, chart tracing means having a fixed law of, operation and including a stylus for following the curve to be integrated, means variably driven in accordance with the movement of said chart tracing means to integrate the curve, a second chart tracing means having a difierent fixed law of operation for use in integrating other types of charts, and motion transmission means operatively connecting said chart tracing means for maintaining the motion thereof proportional.

7. An apparatus as defined in claim 6 in which said motion transmission means comprises intermeshing gears of different diameters.

8. An apparatus as defined in claim 6 in which said motion transmission means comprises links and radial arms of different lengths.

9. A calculating machine comprising a movable chart plate adapted to receive a chart having a. curve thereon to be integrated, means operating from a fixed pivot and operating a stylus for following the curve to be integrated, integrating means variably driven in accordance with the movement of said stylus operating means to integrate said curve and including a cam and means contacting said cam for guiding the movement of said stylus operating means, a second means operating from a second fixed pivot adapted to operate a second stylus for integrating other types of charts, and means connecting said contactin'g means and said second stylus operating v others, means operating from a second fixed pivot adapted to operate a second stylus for integrating other types of charts, and means adapted to connect said second stylus operating means with said cam.

11. A calculating machine comprising a movable chart plate adapted to receive a chart having a curve thereon to be integrated, means operating from a fixed pivot and operating a stylus-tor following the curve to be integrated, a counter, counter driving means, a substantially square root cam for varying the movement of said counter driving means in accordance with the movement of said stylus operatingmeans to register on said counter the integral or the square oot of said curve, a second means'operating frmn a second fixed pivot adapted to operate a second stylus for use in integrating other types of charts, and motion transmitting means operatively connecting said styli operating means for maintaining the angular movement thereof proportional.

12. A calculating machine comprising a movable chart plate adapted to receive a chart having a curve thereon to be integrated, means operating from a fixed pivot and operating astylus for following the curve to be integrated, integrating means variably driven in accordance with the movement of said stylus operating means to integrate said curve and including a plurality of cams, means contacting one of said cams for guiding I the movement. of said stylus operating means, a second means operating from a second fixed pivot adapted to operate a second stylus for use in integrating other types of charts, motion transmitting means operatively' connecting said styli operating means, and shifting means for causing contact between said contacting means and a difierent cam for integrating said other types of charts, said motion transmitting means I remaining in operative relation during the shiit- 'ing operation.

13. A calculating machine comprising a chart plate adapted to receive a chart having differen- ,tial pressure and static pressure curves thereon,

a pair of means for carrying styli adapted to follow said respective curves, means variably driven in accordance with the movement of said styli to indicate the integral of the product of the square roots of said curves, a second pair of means for carrying styli adapted for use in integrating diiferential pressure and static pressure curves of different types of charts, and motion transmitting means operatively connecting said pairs of means respectively for maintaining the mo ion thereof proportional.

14. A calculating machine comprising a chart plate adapted to receive a chart having differential pressure and static pressure curves thereon, a pair of means for carrying styli adapted to follow said respective curves, imeans variably driven in accordance with the movement of said styli to indicate the integral of the product of the,square roots of said curves, and including a substantially square root cam, a second pair of means for carrying styli adapted for use in integrating diflerential pressure and static pressure curves of diflerent types of chartsQand motion transmitting means operatively connecting said pairs or means respectively for maintaining the motion thereof proportional.

15. A calculating machine comprising a chart plate adapted to receive a chart having diflferential pressure and static pressure curves thereon, a pair or means for carrying styli adapted to follow said respective curves, means variably driven in accordance with the movement of said styli carrying means to indicate the integral of V the product of the square roots of said curves, a

means respectively for maintaining the'motion 75 

